Apparatus for producing rubber articles



April 18, 1944.

E. A. LUXENBERGER ETAL APPARATUS FOR PRODUCING RUBBER ARTICLES Filed Aug. 2, 1940 4 Sheets-Sheet 1 INV ENTORS ATTOgEY.

April 18, 1944. E. A. LUXENBERGER Erm. 2,347,117

APPARATUS FOR PRODUCING' RUBBER ARTICLES Filed Aug. 2, 1940 4 Sheets-Sheet 2 SPH m? w Nm/r E54/ O VMM@ H r mm@ A Mu. W5 ...n Aff. 1 6N `l i ma W l 7 r Il; fa v 511-! M llllllllllllllll |l. .|||||l|||||||||||| l, J n. J Z w /f 0% m W f 0l i .0. W 7 Z 2d ad April 18, 1944.

E. A. LUxENBERGl-:R r- TAL 2,347,117l APPARATUS FOR PRODUCING RUBBER ARTICLES Filed Aug. 2, 1940 4 Sheets-Sheet 3 i?? 7 f ff 57X, JZ! T HW/ oa 1 l l l J 4 75 f7 ff l ff E M INVENTORS 0X5 /1/55 Rf/7 Patented Apr. 18, 1944 APPARATUS FOR PRODUCING RUBBER ARTICLES Eugene A. Luxenberger, George W. Blair, and John F. Schott, Mishawaka, Ind., assignors to United States Rubber Company, New York,

N. Y., a corporation of New Jersey Application August 2, 1940, Serial No. 349,748

2 Claims.

This invention relates to molding apparatus, and particularly to continuous apparatus for the production of vulcanized rubber articles, especially where sponge rubber articles are manufactured in a cyclic process from foamed or frothed latex. The apparatus comprises a series of stations at which the various consecutive operations are carried out on one or more molds. The stations are positioned along a closed continuous circuit, and molds are conveyed from station to station at the desired rate. The operating mechanisms at the various stations may be synchronized with the speed of transfer of the molds from one station to the next. The process carried out by the present apparatus is cyclic and continuous, that is, the same series of molds may be repeatedly employed for the production of a large number of articles without removal of any mold from the apparatus. The cycle of operations upon a mold and the material contained therein is such that, when completed, the mold is returned to the initial station in condition for the production of a substantially identical article to the article just completed.

The process involves preliminary preparation of a latex foam ready for pouring into a mold. An open mold is filled to the desired height with a quantity of latex foam, is closed and is transferred during at least part of a coagulating period to a vulcanizer. Coagulation is controlled as to time so that it is completed before vulcanization has commenced. The latex is preferably prepared with the desired ingredients, such as a delayed coagulant for latex and the usual antioxidants, vulcanizing ingredients, etc. vulcanizing station, a newly introduced mold is retained at low temperature, such as at substantially atmospheric temperature, for a suicient time to induce complete coagulation of the latex foam mix. The thus set article is then subjected to an elevated temperature in the presence of steam until the desired degree of vulcanizing is obtained. The mold with the vulcanized article is then withdrawn from the vulcanizer at the vulcanizing station and is returned toward the initial pouring station. The mold is automatically openel in transit, the vulcanized article removed therefrom and the mold is nally cleaned and cooled, if necessary, whereupon it is in condition for a repetition of the cycle.

The apparatus includes generally a mold lling station, a. mold closing station, a vulcanizing station, including means for insuring complete coagulation of the latex foam, a mold opening station. an article removing station, and a clcans At the ing or cooling station, all of such stations being arranged in a circuit in the named order.

The vulcanizing station has timing means for the coagulating and vulcanizing stages synchronized with the rate of feed of unfinished articles from the preliminary stations thereto. When an article or a plurality of articles are introduced into a vulcanizer which may comprise one of a bank of vulcanizers constituting the entire vulcanizing station, a monitor by one movement may initiate the following automatic operations. First, the vulcanizer is closed, next it is sealed, then a coagulating period elapses to insure that the article is set in the proper shape by the mold. The air is then exhausted from the vulcanizer and steam is introduced. The temperature and pressure of the steam are automatically controlled while the vulcanizing operation is in progress, to insure uniformity of articles produced and synchronization of the vulcanizing stem with the other stages in the process, correlation of the rate of transfer of the article from one station to another, and, finally, the production of articles having the desired characteristics.

The instrumentalities for successive operations by the mechanisms of the stations in identical sequence upon a series of articles include the conveying means which operate both Within and outside of the circuit described. The molds are transferred at a constant rate of speed from one station to another with the exception of the vulcanizing station. Before reaching the vulcanizing station each mold is transferred manually to a truck which rides in an endless truck track. The truck carries the mold, preferably together with a number of similarly lled other molds having at least partially coagulated material therein, along the truck track to an open vulcanizer. The entire truck including the desired number of filled molds is introduced manually into the vulcanizer, whereupon the vulcaniiiing` operations are carried out while the molds are in a stationary position within the circuit. When the vulcanizing operation has been completed the door of the vulcanizer automatically opens and the truck is Withdrawn manually and transferred along the truck track to a distributing point where the individual molds are redealt onto the continuous conveyor for return to the pouring station after automatic opening and after removal of the vulcanized articles therefrom. From the distributing point the empty truck is transferred automatically around the endless truck a new batch of molds containing unvulcanized articles.

The apparatus provides a continuous method of producing a plurality of identical molded articles with a minimum of manual operations, thereby insuring speed of production and uniformity of product. With the apparatus a large variety of sponge rubber articles may be produced such as chair seats, mattresses, automobile cushions, etc. One of the advantages of the apparatus is its adaptability to speed up production while maintaining the results of the operations by various stations at a constant. f

A preferred embodiment of the invention may be understood by reference to the accompanying drawings, of which:

Fig. 1 is an overall plan view of the apparatus;

Fig. 2 is an elevation taken along the upper side of the apparatus as shown in Fig. l including the opening, removing, cleaning and'cooling, pouring and closing stations;

Fig. 3 is a vertical cross section of one vulcanizer, showing the door in open position in The general apparatus Molds Il (Figs. 1 and 6) comprise a lower mold section and an upper mold section |2 having projections I3 thereon extending into the lower mold section when the mold is closed. The lower mold section Il is fastened to a lower frame I4 longitudinally hinged at Il to an upper frame Il which holds the upper mold section I2. The upper frame Ii carries a handle l1 adapted to engage cams for the opening and closing of the molds in transit. If desired, the handle may be constructed as a roller which rides along a support bar |3 while the mold is open and also during the process of opening or closing.

'I'he molds travel along tracks 2l, 2| and 22 (Fig. 1) in the portion of the circuit including opening station 23, removing station 24, cooling station 25, cleaning station 2l, pouring station 21 and closing station 23.

An elevator 30 (Fig. l) receives a mold from the track 22 and raises it to the "desired level of a multi-level truck 3| which is carried by a truck frame 32 (Fig. 6) for transfer to the vulcanizers 4| or 42. The elevator may be manually operated or powered by any desired means so long as those means do not interfere with the transfer from the track 22 into the truck frame 32. For example, the usual elevator 30, firmly secured to the floor, may have laterally extending brackets 33 holding a horizontal platform 34 interposed in the path between the track 22 and the truck frame l2. The truck frame 32 is at a receiving point 35 (shown at the left side of Fig. l). A similar truck frame 35 is shown in position (at the right side of Fig. l) at a distributing point 31. A corresponding elevator 33 is shown with a mold Il partly emerging therefrom onto the track 23.

Extending between the receiving point 35 and the distributing point 31 are tracks 40 for the transfer of truck frame-32 to the vulcanizers and then to the position of the truck frame 36. The vulcanizers or vulcanizing tanks 4I are aligned along one side of the track and vulcanizers 42 along the other side, all of which together comprise a vulcanizing station 43. A return track 44 is provided for the transfer of the truck frame 36 back to the position of the truck frame 32 after the molds have been removed.

A mold is automatically propelled along tracks 20, 2| and 22 from the elevator 39 to the elevator 30. A number of molds are placed on shelves of the truck 3|, and the truck is manually moved along the track 40 to one of the vulcanizers 4| or 42. The truck 3| is then Wheeled from the truck frame 32 into a vulcanizer and the vulcanizing operations are initiated. In order that the track 4l may be clear for subsequent delivery of another group of molds into a different vulcanizer, the empty truck frame 32 may either be directly transferred to the distributing point 31 and thence back along track 44 or it may be shifted to a different vulcanizer to receive a'. truck containing molds with vulcanized articles. Considerable flexibility of operation is thus obtainable since the number of vulcanizers used may depend on the rate of travel of the molds I0 around the portion of the circuit exclusive of the vulcanizing station 43. 'I'he operating circuit comprises all of the stations and tracks except the return track 44 for the empty truck frames.

The continuous transferring means As shown in the upper left hand corner of Fig. l, a motor drives a shaft 5| carrying the sprocket 52 which drives a sprocket 53 by a chain 54. The sprocket 53 is keyed to a drive shaft l5 carrying driving sprockets 58 supported in the track framework. As shown best in Fig. 2, drive chains 51 are driven by the driving sprockets 56 and are supported at the other end by idler sprockets 53 keyed to a shaft 50. The shafts 55 and 60 may be mounted in any suitable known manner on the framework holding the track 2|. The drive chains 51 carry hooks or dogs 3| spaced far enough apart so that each dog may engage 50 onlyone mold frame for a mold I0.

the drive rollers 12 may extend entirely across the frame 13 of the turn. while the rollers 1| may be supported between an intermediate curved brace 14 and one side of the frame 13. The drive rollers may be driven by any suitable means from the drive chains 51, as by chains connected to the motor drive shaft 5|. The track 22 may comprise upstanding flanges 15 to hold trays in proper position while travelling around the curve 10. It will be noted that the track 22 is so proportioned that it will hold more than one mold, thereby allowing sufficient' time for the elevator platform 34 to deposit the desired number of oncoming molds into the various levels of the truck 3|.

Referring to the right hand side of Fig. l, it will be seen from the position of the mold handle I1 that molds on the track 20 are reversed with respect to those on the tracks 2| and 22. So that the mold-handles may be on the proper side of track 2| in order to engage the mechanism of the opening and closing stations 23 and 29 respectively, a turning device 80 is provided.

Molds are withdrawn from the platform of the elevator 39 and fed to the turning device by hooks or dogs 8| secured to an endlessrhain 02 on a shaft 84 supported in the framework beneath track 20. The chain 82 is driven by a drive sprocket 85 keyed to a shaft 86, which inturn is driven through miter gears 81 and 89 by a shaft 90 supported on the end of the frame for the track 2|. The shaft-90 is driven through a chain 9| and appropriate sprockets by the shaft 60 which supports the sprockets for the drive chains 51.

The turning device 80 may be of any suitable form and is synchronized with the chains 82 and 51. For example, a. turntable 92 having cross tracks 93 is driven by a Geneva wheel 94 and corresponding cam 95 having a positioning pin 96. The rate of turn of the turntable 92 is determined by a chain 91 driven by sprocket 99 keyed to the shaft 90 and in turn driving a sprocket which is geared to drive shaft |0|. The drive shaft 0| is geared to drive the vertical shaft |02 keyed to the Geneva cam 95. A hook |03 on the chain 9| extends beneath the forward edge of the mold frame to engage the frame when the cross track 93 has turned the mold 90 degrees.

The length of the drive chains 9| and 82, carrying hooks |03 and 8| respectively are so selected that by the time a mold has been placed on track' 2| from the turntable 92 a succeeding mold is in position to enter the turntable at right angles to the first mold, thus preventing interference.

The shaft 84 is positioned'far enough away from the turntable so that, while the cross track 93 is in intermediate turning position, a mold will not have passed far enough along the track to enter the turntable until the turntable has been freed of the preceding mold.

Truck transferring means The only portion of the operating circuit traversed by the truck frames 32 is along the track 40 including the receiving and distributing .points and 31, and back along the return track 44.

supported at one'end by a sprocket 83 revolving Q The mode of travel of the truck frames and trucks will be understood by reference to Fig. 6.

vThe tracks and 44 are overhead tracks which may be suitably supported by framework ||0 suspended from the ceiling. The bottom of the truck frame 32 carries apair`of short sections of track, to support wheels H2, ||2on rotatable axles ||3 journaled in the framework ||4 of the truck 3|.

The truck 3| has a plurality of shelves ||5 for the reception of molds I0. Eachof the shelves preferably carries suitable anti-friction rollers H5. The platforms of the elevators 33 and 39 carry corresponding rollers ||1, mounted in any convenient manner such as by journaling their axles in the longitudinal frame members of the platforms. The elevator is raised or lowered to the proper height to select the proper shelf I|5 for insertion or.'v removal of a mold into or out of the truck, as by a manual sliding operation. At one or-both ends of the shelf I5, are mounted longitudinal stop rods I9, for example, by hinges 29; The stop rods may be swung up into operative position afterya tray or mold has-been inserted and may be swung down below the upper `vthe tracks, one beam fioor of each vulcanizer 42 to receive a truck 3| merely by wheeling it out of the truck frame .32. If desired, auxiliary tracks may be temporarily interposed between theends of tracks and |2| to facilitate transfer of a truck full of molds between the truck frame 'and the vulcanizer, thereby`insuring proper positioning of the truck within the vulcanizer.

The truck frame 32 has a ceiling |30 through which a pair of threaded support rods |3| extend and are rotatably secured in position by upper and lower nuts |32 and |33. The top of the upper frame 32. 'l'he turntable head has secured thereto a beam |39 suspended by the lower arm of a yoke |40 and rotatably secured by bolt |4|. The upper arms of the yoke each carry a. shaft |42 supporting pairs of rollers |43 which rides on a ange |44 of the track 44. As shown in Fig. l, one of the pair'of the turntables |34 is positioned near one end of the truck frame 92, and the other turntable |45 is mounted near the other end.

When the truck frame is travelling along the track 40, the beams-|39 and |46 are parallel to corresponding to each track. At the receiving and distributing stations 35 and 36 respectively, turning them at right angles. Suitable manual or mechanical means may be utilized to perform the turning operation. As the track frame travels along the track 44, the beams are aligned, sov

return operation of the track frame cycle, the truck frame rides on a single y that during this track.

At each ofthe receiving and distributing stations 35 and 31 respectively are a pair of turn-f 'tables |50 and |5I, corresponding to the pair of Track connections- |52 and |53 are l suspended from the turntables which are' rotatably secured to -theframework ||0. The track," connections may be rotated for alignment either tracks 40.

with respect tothe two tracks 40; or maybe turned at right angles so that they Vare aligned with respect to each other and to the track 44.

Thus a truck frame may be transferred fromv along the track 40 whereeach set of'wheels |43 rides on one of the tracks, onto the track connections |52 and |53 as shown by the position of l the truck frame 36. The turntables and |5| may then be turned 90, whereuponr atruck frame may be removed from the track connections and returned from position 31back to position k35. For driving a truck along-track 44, an endless drive chain |54, having a series of drive arms |55 may be suitably supported vin known 4manner by a guide |56 to follow the path of the track 44. The guide `|56 may be supported from the rafters or the superstructure ||0 by brackets |51. A motor |59 may be provided with a chain drive |60 to drive a sprocketv |6| meshing with the links of the drive chain |54. The oppositeend level of the rollers ||6 when molds are being of the course trave'rsed'bythe drive chain may be free or driven, as desired, tofrevolve with la sprocket |62. u 4 n.

The operating stations f g Observingv Fig. 2 fromlleft to-right, various operating stations appear with a series of molds` being transferred along the track 2| in thevdif' the beams may be valigned by rection of the arrows. The opening station 23 comprises a tunnel supporting, by brackets -|1 engages the upper edge of the cam |12, which is shaped like a guide rail, and the upper section I2 of the mold is raised into the vertical position as shown in the vcase of mold |15. As the mold progresses, the mold section is opened even farther and the weight of the handle is shifted over to cam I 13 which lowers it gradually, until it rests, as shown,with handle |1 at |16 on the lowerhorizontal guide rail |9. A cushion or other article |80 may be removed as soon as the jaws of the mold have been separated a suflicient distance. Thus the forwardmost part of the mold opening station 23 may coincide with and constitute the removing station 24.

The articles are manually stripped from the molds at the removing station 24. Since the mold projections I3 in the upper mold section l2 extend into the article |80, the entire article is often automatically lifted bodily from the lower mold section I so that the entire manual stripping takes place from the upper mold section.

The cooling station 25 comprises one or more fans |0| driven by motors |62 which are supported by any suitable framework |83 suspended from the ceiling. .f

The cleaning station 26 may comprise a plurality of pipes (see Fig. 1) |84 from which nozzles |85 extend and point toward the interior of the open upper mold sections. Steam, hot water, or compressed air may be used in conjunction with the nozzles to remove pieces of sponge rubber material which may have been caught between the mold projections |3. These automatic operations may be supplemented by manual operations both on the upper mold sections |2 and the lower mold sections |I. If liquid cleaning means are employed, the molds should be dried before reaching the pouring station 21. The cooling and washing operations may be carried out concurrently or successively as desired. In case they are successive, the track 2| may be elongated and the cleaning station may be positioned adjacent to the cooling station instead of coincident therewith.

The mold-filling or pouring station 21 may be employed in conjunction with a platform |86 on which pouring means may be either iixedly or movably mounted. As shown in the drawing, a truck |81 riding on wheels |88 may support a tiltable vat or tank |89 having a lip |90 adapted to extend over the lower mold section As the molds travel in the direction of the arrow along the track 2|, the truck |81 may be wheeled along the platform |06 while pouring latex foam into the mold. The truck may be withdrawn for reiilling as their contents are used, and other trucks supplied.

The mold closing station 29 operates similarly to the mold opening station 21. When the handle I1 of a mold reaches the forwardmost end of the A horizontal guide rail I9 it engages the upper surface of a cam |9|, corresponding to the cam |12 and supported by brackets |92 in a tunnel or frame |93. After the empty upper mold section shown in the position |94 has reached the vertical position it travels for a moment in a space |99 between the cam |9| and a cam |96 corresponding to the lowering cam |13. At the end jammed across the spaceat the end of track 22 while the elevator is in operation.

The vulcanizng station and controls The vulcanizers 4| and 42 each comprise a cylindrical tank or chamber 200 having a circular door or gate (indicated in Fig. 3 in dotted lines when open), which may be raised or lowered by sliding in a' frame 20|. Brackets 202 retain the door in proper position at all times with respect to the frame 20|. At the top of the frame, hoist reels 203 are motor driven to wind or unwind hoist wires 204 secured at their lower end to brackets 205 on the top of the vulcanizer door. A drain 206 may be provided at the door opening to prevent accumulation of condensed `steam in a trough 201 which receives the edge of the door when closed.

The vulcanizer is automatically operated once its cycle of operations has been initiated by an operator pushing a button. The cycle of vulcanizing operations. including completion of the gelling period for the latex foam, may be adjusted, as by controlling the time and temperature thereof, to synchronously conform with rate of molds being operated upon by the other stations, while still maintaining .the operating conditions at optimum value. For example, the rate of vulcanization may be speeded up when the rate of travel of vulcanizers through the other stations is increased.

In Figs. 3 and 5, 302 designates the door of the vulcanizing tank 42. The door 302 is driven up and down in frame 20| by a motor 304 actuated in either direction by a door operating relay 306 (Fig. 4). Steam is admitted to the tank at 306 and controlled by a valve 309 to be described, and condensed water drained from the tank at 3l l, through a condensate chamber and control valve 3|1, to be described. A vent 3|3 at the top of the tank communicates with an exhaust stand indicated by arrow 3|5, through a vent control valve 3 6, tobe described.

'I'he cycle of operations performed on the tank 42 is as follows. After uncured articles have been placed in the tank 42 ready for vulcanization, the door 302 is closed and locked. 'Ihe temperature and pressure within the tank are maintained normal until suiiicient time has elapsed to complete gelling or coagulation of the latex foam in the mold, thus forming an unvulcanized shaped article. The vent 3|3 is left open and steam is supplied through the steam inlet 306, blowing the air out through the vent. When the tank has been filled with steam, the vent valve 3| 6 is closed by a thermostatic control, to be described and the temperature is thereafter permitted to rise to the desired predetermined level. During the vulcanizing period the temperature within the tank is maintained constant by controlling the steam valve 309 and condensate valve 3|1 controlling a pipe line 3|9 leading to the condensate discharge outlet indicated by the arrow 320. When the temperature within the vulcanizer has been maintained for predetermined length of time, steam valve 303 is shut oi, the vent 3|3 is opened, the door is unlocked. and after the pressure returns to zero, the door 302 is raised, and the vulcanized articles may be withdrawn together with their enclosing molds. The automatic operations just described are performed by the following instrumentalities.

A push button switch 32| (Fig. 8) starts the closing of the door 302 and commences the operation of a timer 322. The timer initiates each step in the operations and determines the length of time allowed within the vulcanizer. A vent controller 323 is provided for operating the vent valve 3| 6 in response to the temperature within the tank which is relayed from a thermometer 324 through a thermometer connection 325. During the vulcanizing cycle, a temperature and condensate control 326 determines and records the temperature within the tank by controlling the steam valve 303 and condensate valve 3|1 in response to the indication of a thermometer 321 through a. thermometer connection 329; and the indications of a. thermometer 330 and thermometer connection 33| within the condensate chamber 3| 2. The temperature and condensate controller 326 takes over from the timer the control of the steam inlet 306 through valve 303 and the condensate drain 3|| through valve 3|1 during the vulcanization stage of the cycle.

The vulcanizer door is locked by two cylinder n locks 332 and 333, diagrammatically shown in Fig. 8 out of position for purposes of clarity. Lock 332 is shown in structural relation to the door in Fig. 5. When the door 302 is closed a piston 334 within the cylinder 322 may be forced forward by introducing air into a rear inlet 335 to drive a. latch plunger 336 through a latch slide 331 in the side of the door. When the piston is all the way forward, so that the door is locked, the plunger closes a normally open spring switch 339 to permit the completion of control circuits, to be described. When it is desired to unlock the door, air is forced through a forward inlet 340 into the cylinder 332 to retract the piston and the switch 339 springs back to its normal open position. A normally closed pressure switch 34| is interposed between the timer 322 and one side of the electric power line.

Three-way pilot valves 342 and 343 indirectly control the operation of the cylinder locks 332 and 333. Another three-way pilot valve 344 permits the operation of the vent valve 3|6 by the vent controller 323. A uid pressure switch 345, closed at low pressure is employed as safety device for preventing the opening of the door 302 while there is still pressure in the vulcanizer at the end of the cycle after the vent 3|3 and the locks 332 and 333 have been opened. A normally closed door motor limit switch 341 is tied in with a normally closed limit switch 349 for stopping the door motor 304 at the lower and upper positions of the door respectively.

A signal lamp 350 lights when there is pressure in the vulcanizer through normally open pressure switch 346. A door gasket (see Fig. 3)

35| may be pressed into sealing position against the door after it is closed by the application of air through pipe 352. A thermometer 353 communicates with the interior of the tank at the rear thereof to indicate the temperature in the tank.

The controlling mechanism is actuated by an electrical circuit, of which there is only one main power line; and air which is supplied into three separate circuits` by three separate air supply lines to be described below.

Electric power is supplied to the controls by lines 356 and 351, and is used to operate timer clock 354, the lamp 350, a timer cam 355 and the door operating relay 305. There are three sources of air supply to the various control mechanisms, the pressures in the various air lines being determined generally by their various functions. A high-pressure air supply 353, for example of the order of pounds per square inch, operates the door gasket 35| and the door locks 332 and 333, depending on the position o! the pilot valves 342 and 343. A relatively low pressure air supply 360, for example of the order of 25 pounds per square inch, is fed into the vent controller 323 and simultaneously into the temperature and condensate controller 326. The vent controller 323 closes the vent valve 3| 6 by passing air thereto from the supply 360, so long as the pilot valve 344 maintains the line open in a manner to be described below. Similarly, the controller 326 opens and closes the steam inlet valve 303 and the condensate drain valve 3|1 by applying or releasing air pressure from the supply source 360. An intermediate air supply 36|, for example 35 pounds pressure more or less, feeds directly into the timer 322 whereby air may be distributed by the timing mechanism, that is, by the operations of the cam 355, to the pilot valves 342, 343 and 344, and to a resetting cylinder 362 within the timer. The timer asa whole is shown in Fig. 3 as enclosed by a dotted rectangle 322. 'I'he air line 36| is directly con nected to each of the valves within the timer and thence t0 the pilot valves, although for the sake of clarity in the drawing the line 36| is shown as stopping at the outside of the timer 322.

Although other timers may be employed, a suitable timing mechanism is the type manufactured by the Taylor Instruments Company and designated for sale as Type 52R. Referring particularly to Fig. 7, the cam 355 is connected by any desired arrangement, such as gears 363, to the electric clock motor 354. The cam 355 may also be rotated by a timing device including a cylinder 362 to actuate gears 364 in mesh with a gear 365 connected to the cam shaft 366 by a clutch 361. A timing piston 363 in the cylinder 362 may be driven forward to set the timing oi the vulcanizing period by introducing air under pressure at the rear inlet 310 in the cylinder until a. bar 31| on a. piston rod 312 of the piston 363 hits a variable stop nut 313 movably mounted on a threaded rod 314. An indicator 315 on the stop nut shows its position relative to a scale 316 which is calibrated in minutes of cure." The bar 31| xed on thepiston rod carries a toothed rack 311 slotted at 319 to receive supports 330, and which meshes with the uppermost gear 364. As the piston travels forward (to the right in Fig. 7), the rack 311 likewise rides forward, driving the gear 364 and rotating the cam 355 an amount determined by the position of the stm 313.

The periphery of the cam is notched at positions 36|, 333, 335, 331 and 333, which determine the operations of the cycle'performed automatically by each vulcanizer 42. A cam follower 330 is supported by a branched timing lever 33| which is pivoted at 332. The upper terminal 333 of the timing lever 33| may be engaged by a catch 334 having a tapered terminal-engaging surface 335 and a notch 336. The catch may draw the cam follower halfway out of the notch 39| as the cam 355 rotates in the direction of the arrow. Further right-hand movement of the terminal 393 will disengage the latch 396 and allow return to the normal upward position. The side of the lever 39| to the left of the pivot 992 carries anI arm 399 and a bifurcated yoke 400 comprising an upper arm 40| and a lower arm 402. A single pole single throw normally open switch 403 has a depending adjustable tappet 404 and may be raised into the closed position by the arm 399 to close the circuit leading from the electric power line 356 to the relay in the limit switch 341. A single pole double-throw switch 40S-may be shifted from the lower to the upper position by raising an adjustable tappet 406 by the arm 399. When the switch 405 is in the lower position, the electric power line 356 is closed as far as pressure switch 345, which is in normally closed position when'the pressure is zero and completes the circuit through the opening side 401 of the door operating relay 305 (see Fig. 8). When the switch is in the up position, that is, when the arm 399 is` raised, that circuit is broken and a circuit is made from the line 356 directly to the closing side 409 of the door operating relay 305. A series of diaphragm valves 4|0, 4||, 4|2, and 4|3 are all connected to the air supply 36| and are actuated by the movement of the yoke 400 of the pivoted frame 39|. These valves are open when their valve stems are pressed inwardly, and closed when the stems are in the out position. When the leftside of the frame is all the way down, tappets 4|4 and 4|5 hold the valves 4|0 and 4|| open since the upper arm 40| is down; and the valves 4|2 and 4|3 are held in their closed position since the tappets 4|6 and 4|1 are "out by virtue of the depressed position of the arm 402. Each of these valves is provided with an air-leak arrangement so that when the pressure is taken or! of its diaphragm valve, the air in the line may be dispelled.

When the valve 4|0 is open, air from the supply passes through a pipe 4|9 and into the cylinder 362 through an inlet 42.0 to force the piston 369 into the "in position (Fig. 8) When valve 4| is open, air from the supply 36| enters main pipe line 42| and branch line 422; pressure in air line 422 actuates the diaphragm of the pilot valve 344 to open a vent 423 of the vent valve 3|6 which assumes its normally open position; pressure in air line 42| actuates one of the two diaphragms of the steam valve 309 to close that valve. When the valve 4|2 is opened, air is admitted from the source 36| through a pipe 424 to depress the diaphragm of the pilot valve 343, thereby opening a line 425 between the air supply 359 into the rear inlets 335 of the cylinders 332 and 333 to lock the vulcanizer door and into the pipe 352 for the door gasket 35|. Air pressure also is admitted through a pipe 426 to the diaphragm of the pilot valve 342, closing oi an inlet 421, and opening a vent in valve 342. This permits the forward inlets 340 of the door locks 332 and 333 to vent at opening 428 in valve 342 to permit the locks to be pushed out into locking position. When the valve 4|3 is open, air is fed from the air supply 36| through a pipe 430 to the rear inlets 310 of the cylinder 362.

The vent controller 323 may be of the type sold by the Taylor Instrument Company as the Fulscope Indicating Controller No. 8'1-R, (Type 3) and has a limit hand 43| which may be set to regulate the temperatur at which the vent valve 3|6 will be closed, e. g.- 212 F. This controller keeps the vent closed during the vulcanizing cycle so that temperature of 212 will keep valve closed. An indicating hand 432 records the temperature taken by the thermometer 324 inside the tank 42. When the vent controller 323 starts operating, that is, after the tank has been filled 10 with steam so that the temperature hand 432 reaches the 212 F. set by the limit hand 43|, a valve is opened inside the controller 323, thereby admitting air from source 360 to the diaphragm of the vent valve 3|6, thereby closing it. As

stated above, the position of the pilot valve 344 determines whether the vent controller 323 can actuate the vent valve.

The temperature and condensate controller 326 may be of the type manufactured by the Taylor Instrument Company and sold as Dubi-Duty Fulscope Controller. The controller 326 may be provided with a recording device, and operates similarly to the controller described above,

except that it controls two valves instead of one.v The maximum setting 433 for the temperature within the tank should be equal to the setting on the limit hand 43| on the vent controller 323. A temperature hand 434 is actuated by the therymometer 321 within the tank, and so long as the temperature hand records lower than the setting hand, a throttling diaphragm valve 435 operable by the temperature hand 434 of the controller in known manner remains closed to prevent the air supply 360 from entering a pipe 436 to close the steam valve 309. When, however, the

temperature is equal to or greater than the maximum set by the hand 433, the valve 435 opens, admitting air from the supply -360 to the other diaphragm of the steam valve 309, to close the o valve, thereby shutting oi the steam supply in order to prevent the temperature from continuing to rise. A similar throttling valve 431 is placed in the line between the air supply 360 and a pipe 438 which enters the top of the condensate valve 3|1 above the diaphragm. The control of condensate out of the chamber 3|2, is dependent on the temperature therein as recorded on the themnometer 330 which actuates'a thermometer hand 439. The minimum temperature for the condensate chamber may be predetermined by setting a hand 440 at the desired position. When water passes out of the condensate chamber 3|2 through the normally open valve 3|1 to the discharge outlet 320, steam from the tank raises the 55 temperature in the thermometer 330 actuating the hand 439 to keep the valve 431 open and thereby to allow air to flow from the supply 360 to the diaphragm of the valve 3|1, closing the valve. As condensate water again collects in the 00 chamber 3|2 and the temperature lowers, the

hand 439 will eventually coincide with the hand 440 closing the valve 436 and releasing the pressure on the diaphragm Qf the condensate valve 3|1 to open it and again discharge the water from the cham-ber 3|2. This throttling operation continues during the entire vulcanizing cycle .and prevents excess of condensate from collecting in the bottom of the tank 42. Suitable switches are provided in known manner to operate at the beginning and end of the timer cycle to operate the motor forward or in reverse to open or close the vulcanizer door.

The cycle of operation controlled by the timer 322 and associated mechanism is as follows, after unvulcanized articles including only partially coagulated latex foam articles have been introduced into the vulcanizer 42.

When the push button switch 32| (Fig. 8) is closed, the solenoid 391 is energized, depressing the catch 396 (Fig. 8) the cam surface 395 of which slides along the edge of the terminal 393 to pull the cam follower 390 halfway out of the groove 38|. The terminal 393 is caught above the cam surface 395 in the catch 396 and is locked in that position by the latch 398. As the cam follower is in this half way position, away from groove 38| the frame 39| is rocked far enough on the pivot 392 to change the position of switches 403 and 405, and valve 4|0 by moving the tappets 404, 406, and 4|4, respectively, upward. This movement actuated by the solenoid simultaneously changes three conditions in the system.

Referring to Figs. '1 and 8, when the cam follower 390 was in the bottom of the cam notch at 38|, switch 403 was open, preventing the clock 354 and cam 355 from running; switch 405 was in the down position, supplying current to the high-pressure safety switch 345, which when the vulcanizer steam pressure dropped to zero gauge, in turn energized the connection 401 of the door operation relay 305 to open the door; valve 4I0 was open, hence timing piston 369 was in its retracted position as shown in Fig. 8; valve4|| was open, supplying air pressure to close the steam valve 309; valve 4| 2 was open, hence no pressure was in the air lines 424 and 426, therefore the door locks were retracted or unlocked; valve 4|3 was open, hence the piston 369 could not reset the timer. Moving the cam follower 390 to a position 44| (between positions 38| and 383) so tilts the frame 39| that the switch 403 is closed, switch 405 is changed to the up position, and valve 4|0 is closed. 'Ihrowing the switch up starts the door down so that when the bottom of the door hits the arm 442 ofthe lower limit switch 341 a relay contained in the limit switch closes and the cam 355 is started since the circuit through the switch 403, the clock motor 354, the limit switch relay 341, and the normally closed pressure switch 34| is made. Closing the valve 4I0 releases the pressure from the line 409 so that when the cycle has further operated the re-set cylinder 362 may perform its function.

The cam then rotates counter-clockwise as seen in Fig. '1 so that the follower is in position 383, which further pushes lower arm 402 of the frame upward to open the valve 4|2, admitting air into the pipe 424 and the pipe 442 to open the pressure switch 34| breaking the clock circuit and stopping the cam temporarily. The air also presses the diaphrgams of the pilot valves 342 and 343, respectively, thereby shutting olf air from the source 359 to the inlet 421 of valve 342 and opening the vent 428 of valve `342 while closing oi the vent 444 in the valve 343 and admitting air from the source 359 to enter the cylinders 332 and 333 and the gasket inlet 352. If the door is in proper closed position, each piston 334 advances the plunger 336 into position within the latch slide 331 so that the door is sealed and locked. If the door is improperly closed, the cycle of the cam remains stopped until this situation is rectified since at this moment the clock motor 354 is not running. When the door is properly closed and the plungers enter the lockholes, both door lock relays 339 and 342 are closed and the open pressure switch 34| is shunted. thereby closing the clock circuit and re-startlng the clock motor 354.

The gell portion of the cycle is then timed by the travel of the cam 355 along the cam follower 39| until the follower reaches the next elevation 395. This gell period may be adjusted, for example, from one to ten minutes, by rotating a slide portion on the cam into proper position and locking it. During the gelling period, the steam is shut off by the steam valve 309 since its diaphragm is still depressed by air pressure admitted through the open valve 4| I; and the vent 3|3 is open since the vent valve 3 I 6 is in its normal open position.

The vulcanizing cycle starts when the cam follower rotates, at position 385. This further raises the frame 39| so that the upper arm 40| closes the valve 4|| and the lower arm 402 opens the valve 4|3. Opening the valve '4|3 admits air into the re-set cylinder 362 to push piston 369 forward until the bar 31| hits the stop 313, thereby moving the train or gears 364 to rotate the cam counterclockwise until the portion of the periphery between the cam follower 390 and the position 381 represents the time of the vulcanizing period. Closing the valve 4|| releases pressure from the upper diaphragm of the double diaphragm steam valve 309 and allows controller 326 to take over control of inlet steam by passing or shutting oil' air to the lower diaphragm. .At the same time pressure is thereby released from the diaphragm of the pilot valve 344 permitting it to rise to the upper position so that vent 423 is closed and circuit from vent valve 3|6 to controller 323 is opened. This sets into operation the vent controller 323 which, as described above, closes the vent valve 3|6 in response to the attaining of a predetermined temperature of the vulcanizer set by the limit hand 43 I. Referring now to the steam control 326 since the temperature hand 434 is below the limit set by the hand 433, at least at the beginning of the cycle, the steam valve 309 opens. The steam entering the steam inlet 306 within the tank drives the air through the vent\x,3|3, until the temperature measured by the thermometer 321 near the vent 3I3 causes the hand 432 to rise to the position determined by the hand 43| in vent controller 323, which causes the vent valve 3 I6 to close as described above. When the pressure in the tank has risen to the predetermined limit, for example three pounds, it operates through a line 44| to close the normally open pressure switch 346, thereby completing the circuit through the lamp 350 which remains lighted until the pressure drops again to zero,

During the vulcanizing period, the actual operations of maintaining the temperature at the proper level are controlled by the throttling action, described above, of the temperature and condensate controller 326. When the condensate in the chamber 3|2 reaches too low a. temperature, the thermometer hand 439 closes the valve 431 shutting off pressure in the line 438 and allowing the normally open condensate valve 3|1 to open and the condensate to drain at the outlet 320. As this happens, steam enters the condensate chamber line 3|| from the vulcanizing tank 42 and again raises the temperature in the thermometer 330 which actuates the temperature hand 439 to again close the valve 3|1. The steam inlet 306 is similarly controlled by the temperature hand 434 which opens the valve 435 to close the steam valve 309 when the temperature tends to go higher than the predetermined control point. Both of these throttling actions take place independently throughout the vulcanizing period.

At the end of the vulcanizing period, the cam n follower drops into the notch` 381 and the reverse of the above operations begins to take place. The valve 4 I 3 is again closed by movement of the timing lever 39| and pressure is released from the line 430 leading to the reset cylinder 362 permitting this later to be retracted or reset. At the same time, the valve 4|I is opened, shutting of! the steam by means of the line 42| leading to the upper diaphragm of the double diaphragm steam valve 309. This air pressure also operates the vent pilot valve 344 so that air from the' supply 360 is blocked oil', and pressure on the diaphragm of vent valve 3|6 is released through vent 423 allowing vent valve 3|6 to open, thus throwing the vent controller 323 out of operation. Steam within the tank may then blow through the vent 3|3 as the cam follower travels from position 381 tc fall into the notch 389.

When the cam follower arrives at notch 389, the valve 4|2 is closed so that pressure is released from the pressure switch 34| to close it; pressure is likewise released from the air inlet 352 to release the seal around the door. The pilot valve 343 is opened with respect to vent 444 and the line 425 is closed. At the same time the pilot valve 342 has its vent closed and air is admitted through the line 421 from the supply source 359. This pressure is transmitted through the line 429 to the forward inlets 340 of the door locks 332 and 333 to withdraw the plungers 336 from the latch slides 331. 'I'he shunt circuit through the door lock relays 338 and 342 is broken, but this does not stop the clock motor 354 since the pressure switch 34| has just previously been closed, as described above, to complete the clock circuit.

When the cam follower drops at the starting position at notch 38|, the valve 4|0 is opened to return the timing piston 369 to its starting position. At the same time the switch 403 is opened to stop the clock and the switch 405 falls into the lower position which re-directs the power line circuit through pressure switch 345. When the pressure within the tank, as measured by the line 44| connected to the pressure switches 345 and 346, drops to zero, the switch 345 closes the circuit from the line to the opening side 401 operating the door relay 305 to reverse the motor 304 and raise the door 302. The lamp 350 goes out asthe pressure within the tank drops to zero since the switch 346 is normally open at zero pressure as measured by the line 44| connected with the interior of the vulcanizer.

When the door 302 reaches its top position, it opens the limit switch 349 which is connected in series with the door motor 304 to keep the door open. The vulcanized articles are then withdrawn from the tank 42 and the tank is allowed to cool down to -100 F., at which time it is in condition to receive another truck full of uncured articles. After this truck has been locked in proper position, the push button switch 32| is again closed and the cycle of operations above described is repeated.

Having thus described our invention, what we claim and desire to protect by Letters Patent is:

1. Molding apparatus comprising in combination a support, mold-conveying means movable' continuously along the support, a mold adapted to travel along said support in open position, means for connecting the mold to the conveying means, mold filling means disposed above the level of the mold, a support for said filling means disposed along said support, said filling means being adapted to travel along said last mentioned support, a closing station located after the limit of travel of the filling means as regards the direction of movement of the conveying means, and means responsive to movement of the mold to said station for closing the mold while the mold is moving continuously along the support.

2. Molding apparatus comprising in combination a support, mold conveying means movable continuously along the support, means for connecting a mold to the conveying means, an opening station, means responsive to movement of the mold to said opening station for opening the mold while moving continuously along the support, a closing station, a cooling station and a lling station along the conveying means between the opening and closing stations, means responsive to movement of the mold to the closing station for closing the mold while moving continuously along the support, said mold being adapted to move continuously through said opening station, cooling station, filling station and closing station, and means movable along the support for filling the mold while moving continuously between the cooling station and the closing station.

EUGENE A. LUXENBERGER. GEORGE W. BLAIR. JOHN F. SCHOTT. 

